The inventor of the present invention proposed an apparatus and method for manufacturing metal scrap compression materials as disclosed in Korean Patent No. 10-1134916 issued Apr. 17, 2012, entitled “Metal Scrap Compression Material and Manufacturing Apparatus and Manufacturing Method thereof” to Lee Tae Ho (hereinafter, referred to as “the cited reference”), in which the compression materials can be efficiently melted and the inner layer thereof can be observed.
The cited reference relates to metal scrap compression materials having at least one through-hole and an apparatus and method for manufacturing such metal scrap compression materials. The scrap compression materials are manufactured using a metal scrap compression apparatus, as shown in FIG. 1 to FIG. 3. The metal scrap compression apparatus includes a well-known metal scrap compression arrangement which includes a first compression cylinder 110 disposed at one side of a compression chamber, a first press plate 150 which is moved by a piston thereof inside a first compression space 300, second compression cylinders 110 disposed at both sides of the compression chamber, second press plates 160 which are moved by pistons thereof inside a second compression space 400, a discharge plate 502 positioned at the center of a second compression space 400, and means for opening and closing the discharge plate 502. In addition, in the metal scrap compression apparatus, at least one core 201 is erected at the center of the second compression space 140 such that it is orthogonal to first and second compression directions of the compression chamber 140. The core 201 is also caused to protrude and retract by a core cylinder 200 which is additionally disposed.
Since metal scrap compression materials which are manufactured by the cited reference as above have at least one through-hole, when these metal scrap compression materials are loaded into a melting furnace, molten metal not only contacts the circumference of the metal scrap compression materials but also permeates into the central portions of the metal scrap compression materials through the through-holes. Consequently, the metal scrap compression materials can be melted at a fast rate like small pieces of metal scrap compression materials, thereby greatly reducing the amount of energy that is consumed in the manufacture of metal products.
In addition, according to the manufacturing apparatus of the cited reference, when forming the through-hole in the metal scrap compression material, the metal scrap around the core 201 is first compressed in the first low-density compression process of compressing the metal scrap, and the compression of the metal scrap is completed in the second high-density compression process of compressing the metal scrap. It is therefore possible to minimize friction and stress that are applied to the core 201 from the metal scrap during the compression process.
In particular, in the cited reference, the length of the core 201 that is exposed inside the compression chamber in order to form the through-hole in the metal scrap compression material is set to the length of the actual through-hole of the metal scrap compression material. In the first and second compression processes, bending stress due to a variation in the density of the metal scrap is minimized. Furthermore, since the core itself is short, deformation is minimized, thereby significantly improving endurance. Accordingly, the apparatus can operate reliably and its longevity is increased.
Furthermore, in the cited reference, the first and second compression processes are carried out after the metal scrap has been loaded in the state in which the core is erected in the compression chamber. It is therefore possible to prevent the metal scrap from being caught between the core 201 and the cover 601 and between the core 201 and the bottom of the compression chamber 140, which would otherwise obstruct the operation, irrespective of the shape or type of the metal scrap. Accordingly, the apparatus can smoothly and reliably operate.
As mentioned above, the cited reference is configured such that the metal scrap is compressed twice in the first and second compression processes while surrounding the core 201, and the length of the core that corresponds to the length of the actual through-hole is exposed, unlike in a traditional metal scrap compressing apparatus. Therefore, the apparatus of the cited reference exhibits advanced properties, such as high strength and toughness, little bending or deformation, irrespective of high-pressure friction being applied to the metal scrap, increased longevity and a minimized possibility of breakdown. According to the cited reference, however, a minimum amount of time (e.g. 160 seconds) is required for the entire process of manufacturing one compression material from the metal scrap. The manufacturing process includes loading the metal scrap for first and second compression processes, starting the first compression using the first compression plate 150 by actuating the first compression cylinder 110, starting the second compression using the second compression plates 160 after the first compression is complete, and discharging the compression material after the second compression is complete. However, in this manufacturing process, it is difficult to further decrease the overall process time, thereby productivity cannot be increased, which is problematic.
Although a method for fabricating, constructing and using two or more apparatuses for manufacturing metal scrap compression materials can be considered, this requires an enormous manufacturing cost and the area required to accommodate the facilities is doubled. In addition, a labor cost is inevitably doubled in order to operate the two individual apparatuses. Therefore, the introduction of a more efficient apparatus for manufacturing metal scrap compression materials is required.